This application is related to U.S. patent application entitled xe2x80x9cThermoplastic Air Bag Cover Mountable Onto An Air Bag Container Assemblyxe2x80x9d filed on the same date as this application and having the same assignee as this application. This application is hereby incorporated in its entirety by reference herein.
1. Technical Field
This invention relates to a snap-on thermoplastic air bag covers.
2. Background Art
Thermoplastic air bag covers are widely used. Examples of such air bag covers can be found in the following U.S. Pat. Nos. 3,539,200; 5,062,661; 5,487,557; 5,465,998; 5,549,323; 5,558,364; 5,498,026; 5,520,412; 5,542,694; 5,501,485; and 5,683,101. Snap-on air bag covers are shown in the following U.S. patent numbers. from the above list: U.S. Pat. Nos. 3,539,200; 5,465,998; 5,498,026; 5,501,485; and 5,683,101.
Injection molding apparatus for forming such air bag covers typically have a first mold half having a first molding surface to form a first part of an air bag cover-defining cavity and a second mold half having a second molding surface to form a second complementary part of the air bag cover-defining cavity. The first and second molding surfaces form the air bag cover including a front cover panel and separate resilient clip members integrally formed with the front cover panel. Each of the clip members typically has a front engagement section, a rear shoulder section, and a snap-on groove extending therebetween for snapping the air bag cover onto a retaining member of an air bag assembly.
Typically, the mold parts which form the resilient clip members of the air bag cover are formed to facilitate removal of the air bag cover upon completion of a molding cycle. An operator grabs the molded air bag cover and snaps it off the mold parts forming the clip members. Such manual removal of the air bag cover from the injection molding apparatus is undesirable for many reasons.
Other plastic air bag covers are disclosed in the following U.S. Pat. Nos.: 5,064,217; 5,686,490; 5,280,946; 5,314,203; 5,338,060; 5,342,086; 5,369,232; 5,577,766; 5,630,617; 5,775,728; and 5,794,968.
U.S. Pat. No. 5,603,968 discloses molding apparatus for snap-on air bag covers including a plurality of core members which are movable between retracted and extended positions with respect to one of the movable and fixed mold halves. The core members define a molding cavity along with the movable and fixed mold halves when the core members are in their retracted position.
U.S. Pat. No. 5,922,368 discloses a robust injection molding apparatus for molding snap-on thermoplastic air bag covers on a production basis. The injection molding apparatus includes a plurality of outboard mold parts for molding thermoplastic air bag covers wherein each outboard mold part forms a clip member of the air bag cover including its front and rear sections and snap-on groove therebetween.
However, the molding apparatus disclosed in the prior art is still relatively complicated to make snap-on covers on a consistent basis.
An object of the present invention is to provide a snap-on thermoplastic air bag cover with enhanced moldability wherein the air bag cover is easy to mold and does not require extensive part fill out.
Another object of the present invention is to provide a snap-on thermoplastic air bag cover with enhanced moldability wherein the air bag cover is relatively easy and inexpensive to mold and still provides a snap-on feature.
In carrying out the above objects and other objects of the present invention, a snap-on thermoplastic air bag cover with enhanced moldability is provided. The air bag cover is mountable onto an air bag container assembly including a container having a retaining member and a retaining bracket secured to the container to move therewith. The cover includes a front panel having inner and outer surfaces and adapted to overlie an uninflated air bag contained within the container. The cover also includes a plurality of side walls connected to and extending rearwardly from the inner surface of the front panel. The cover further includes a locking block connected to and extending inwardly from each of the side walls. Each locking block has an extending snap-on groove in a first surface of the locking block facing the inner surface of the front panel. The locking blocks are adapted to cooperate with the retaining member for affixing the air bag cover to the air bag container. Each locking block is characterized in cross-section as having a resilient beak portion for contacting the retaining member during mounting onto the container. The snap-on grooves facilitate resilient displacement of the beak portions. A rearwardly facing surface of at least one of the locking blocks prevents movement of the retaining bracket and the retaining member toward the inner surface of the front panel during mounting of the air bag cover on the container to secure the retaining member within the snap-on groove.
Preferably, the at least one of the locking blocks has a first groove defined in the rearwardly facing surface. In this way, the at least one locking block is adapted to receive and retain the retaining bracket within the first groove.
The cover is preferably molded from a resilient thermoplastic material such as a thermoplastic rubber.
The advantages accruing to an air bag cover as described above are numerous. For example, the resulting air bag cover is easy to mold and does not require extensive part fill out. Also, the air bag cover is relatively easy and inexpensive to mold and still provides the desirable snap-on feature.
The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.